Radiographic assessment of the severity of thumb carpometacarpal osteoarthritis in the dominant and non-dominant hand: a descriptive, cross-sectional study

Abstract

a. Purpose: thumb carpometacarpal osteoarthritis is a disabling condition that can lead to pain at the base of the thumb and impairment of hand function. Considering that usage of the hand is within the risk factors for hand osteoarthritis and that the dominant hand is more demanded in occupational activities, especially during tasks that require precision pinches, the purpose of this study was to compare the radiographic changes at the carpometacarpal (CMC) thumb in the dominant and non-dominant hand. b. Methods: we studied 108 (19 male and 89 female) subjects, between 40 and 80 years old, with radiographic changes of the thumb CMC joint. The individuals represented 65% of the participants enrolled in a group education programme for patients with knee osteoarthritis (OA) in the Institute of Orthopaedics and Traumatology of Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Patterns of the use of the hand was varied among the subjects, including occupations such as housekeepers, secretaries, seamstress, teachers, nursing assistants, workers of metallurgical plant, etc. Two orthopedic surgeons assessed bilateral thumb CMC joint radiographs according to Kellgren and Lawrence (KL) scale. The participants were asked by telephone call or in their follow up visit which was their dominant hand and what was the main occupational activity they did most during the last years. We examined the data for correlation between the grades of severity of osteoarthritis in the thumb CMC, handedness and occupational usage of the hand. c. Results: 25% (95% CI: 18-33) of the 108 subjects had a higher KL grade in the thumb CMC of the dominant hand comparing with the non-dominant (dominant KL mean: 2; non-dominant KL mean: 0,75; range1 to 4) ; 18% (95% CI:10-25) had a higher KL grade in the thumb CMC of the non-dominant hand (non-dominant KL mean: 2,35; dominant KL mean: 1; range 1 to 4); and 55% (95% CI: 45-64) had no difference in the severity of the thumb CMC comparing the dominant with non-dominant hand (KL mean 1,7; range 1-4). We did not find an association between occupational use of the hand and severity OA of the thumb CMC joint because there were too many subgroups of occupational activities and patterns of use of the hand. d. Conclusion: The results suggest that there is no association between joint destruction and the overuse of the thumb CMC of the dominant hand comparing with the non-dominant hand in individuals with thumb CMC and knee osteoarthritis. In this sense, our initial hypothesis seems to be not true. Comparison and analysis of pain and hand function in dominant and non-dominant hand will possibly show different findings. Correlation between occupational use of the hand (work activities) and thumb CMC severity OA should be done with a bigger or more homogenous sample.